/Engine/Source/Editor/UnrealEd/Public/Kismet2/KismetDebugUtilities.h
Looks along the outer chain to find the owning world and disallowing breaking on tracepoints for editor preview and inactive worlds.
static bool TracepointBreakAllowedOnOwningWorld ( const [UObject](API\Runtime\CoreUObject\UObject\UObject) * ObjOuter )